Deck 6: Where It Starts-Photosynthesis

Question 1

-In the accompanying figure, letter F represents ____, a product of light-dependent reactions in both the cyclic and noncyclic reactions.

A)ATP
B)oxygen
C)carbon dioxide
D)water
E)hydrogen ions

Answer 1

ATP

Question 2

Which molecule is produced by the light-dependent reactions of the cyclic pathway?

A)sugar
B)NADPH
C)oxygen
D)ATP
E)water

Answer 2

D

Question 3

-According to the accompanying diagram, in which plant cell structure do the light-independent reactions occur?

A)A
B)B
C)C
D)D
E)E

Answer 3

B

Question 4

During light-dependent reactions, ____ accumulates inside the thylakoid compartment.

A)glucose
B)hydrogen ions
C)O₂
D)CO₂
E)ATP

Question 5

Four of the five molecules listed below take part in the light-independent reactions. Select the exception.

A)water
B)carbon dioxide
C)RuBP (ribulose bisphosphate)
D)PGAL (phosphoglyceraldehyde)
E)PGA (phosphoglycerate)

Question 6

​Why is photorespiration an inefficient way to produce sugars?

A)​Photorespiration produces 7-carbon carbohydrate molecules instead of 6-carbon sugars.
B)​The increased production of O₂ during photorespiration generates excess dangerous free radicals.
C)​Photorespiration only occurs during the night, when the light-dependent reactions are inactive.
D)​CO₂ is lost instead of being fixed and ATP is required to detoxify the ammonia that is produced.
E)​Carbon fixation requires an extra turn of the Calvin-Benson cycle for each molecule of sugar produced.

Question 7

​How does the cyclic pathway of light-dependent reactions differ from noncyclic reactions?

A)​Photolysis is performed by photosystem II in the cyclic pathway, but by photosystem II in the noncyclic pathway.
B)​The noncyclic pathway uses electrons from water to produce ATP, while the cyclic pathway uses electrons from water to produce sugars.
C)​The noncyclic pathway evolved before the cyclic pathway and does not produce sugars.
D)​The cyclic pathway evolved before the noncyclic pathway and does not produce oxygen.
E)​Although the noncyclic reactions evolved first, carbon fixation occurs in both cyclic and noncyclic reactions.

Question 8

Which enzyme catalyzes the process of carbon fixation?

A)RuBP
B)ATP synthase
C)PGAL
D)rubisco
E)thylakoid kinase

Question 9

-According to the accompanying diagram, the electron transfer chains of the light-dependent reactions are located in which plant structure(s)?

A)A only
B)B only
C)D only
D)E only
E)A and C

Question 10

​Under intense sunlight, ____.

A)​the noncyclic pathway produces excess ATP
B)​the noncyclic pathway stalls and the cyclic pathway provides extra ATP
C)​excess free radicals are used to generate ATP for sugar production
D)​the noncyclic pathway becomes dominant as photosystem II stops releasing electrons
E)​carbon fixation ceases and leaf cells become dormant

Question 11

​Burning fossil fuels results in a net increase in the amount of CO₂ released into the atmosphere because ____.

A)​it releases more CO₂ than burning renewable fuels such as wood
B)​photosynthetic organisms cannot recapture all of the CO₂ emitted by the burning of fossil fuels
C)​it releases CO₂ but burning renewable fuels such as wood does not
D)​the release of CO₂ is exacerbated by the production of CO₂ during photorespiration
E)​the reactions that release energy and CO₂ from organic molecules differ from the reactions of aerobic respiration

Question 12

Chlorophyll a absorbs which color(s) of light?

A)red only
B)green only
C)violet only
D)red, violet, and orange
E)red, violet, and green

Question 13

Twelve PGAL molecules form when six carbon dioxide molecules are attached to six RuBP molecules. Only two of these PGAL molecules are needed to form a 6-carbon sugar. What is the fate of the 10 remaining PGAL molecules?

A)They are degraded.
B)They are converted back to carbon dioxide.
C)They are stored as extra PGAL molecules.
D)They are used during photorespiration.
E)They are converted to RuBP molecules.

Question 14

During times of high sugar production, some PGAL molecules that remain in the chloroplast ____.

A)​undergo carbon fixation by ATP synthase
B)​are assembled into lipid molecules
C)​are assembled into starch molecules
D)​are used to produce sucrose
E)​are exported to the plant's vascular tissue

Question 15

In Engelmann's 1882 experiment, why did bacteria cluster in areas of red or blue wavelengths of light?

A)The bacteria used light of those wavelengths for photosynthesis.
B)Algae photosynthesized most efficiently at those wavelengths, producing needed oxygen.
C)The bacteria produced oxygen most efficiently using red and blue light.
D)Algae photosynthesized most efficiently at those wavelengths, producing needed carbon dioxide.
E)The bacteria were attracted to bright light.

Question 16

Why do the cells of photosynthetic organisms contain accessory pigments?

A)Accessory pigments provide a backup source of energy if the main pigment type fails.
B)Accessory pigments direct light toward the primary pigment.
C)Accessory pigments optimize the amount of energy that can be harvested in specific environments.
D)Accessory pigments provide structural support for the primary pigments.
E)Accessory pigments allow photosynthesis to occur at any time of the day.

Question 17

Discrete packages of light energy are called ____.

A)pigments
B)photons
C)chlorophylls
D)radioactive waves
E)electromagnetic particles

Question 18

Light-dependent reactions in plants occur in the ____.

A)thylakoid membrane
B)plasma membrane
C)stroma
D)cytoplasm
E)stomata

Question 19

The electrons that are accepted by NADP⁺ to form NADPH during the noncyclic pathways of the light-dependent reactions are emitted by ____.

A)photosystem I
B)hydrogen ions
C)glucose
D)sunlight
E)ATP synthase

Question 20

-According to the accompanying diagram, where are hydrogen ions sequestered?

A)A
B)B
C)C
D)D
E)E

Question 21

Chlorophyll a, the most common photosynthetic pigment in plants, ____, giving plants their green color.

A)absorbs light of low wavelengths (400-500 nm)
B)reflects green light
C)absorbs yellow and blue light
D)absorbs green light
E)reflects red and yellow light

Question 22

What are the products of the light-dependent reactions of photosynthesis?

A)ADP, NADP+, and sugars
B)ADP, NADP+, and O₂
C)ATP, NADPH and O₂
D)ATP, NADPH, and CO₂
E)ATP, NADPH, and sugars

Question 23

The oxygen released during photosynthesis originates from ____.

A)carbon dioxide
B)glucose
C)ribulose bisphosphate
D)water
E)atmospheric oxygen

Question 24

The enzyme rubisco fixes carbon by attaching CO₂ to ____.

A)phosphoglycerate (PGA)
B)ribulose bisphosphate (RuBP)
C)phosphoglyceraldehyde (PGAL)
D)glucose
E)oxaloacetate

Question 25

Chlorophyll is found ____ of a plant cell.

A)on the outer chloroplast membrane
B)inside the mitochondria
C)in the stroma
D)in the thylakoid membrane
E)in the plant cell wall

Question 26

-In the accompanying figure, the reactions at letter B ____.?

A)are driven by ATP
B)generate water
C)produce NADPH
D)are dependent on light
E)produce O₂

Question 27

Four of the five items listed below are associated with light-dependent reactions. Select the exception.

A)photolysis
B)electron transport phosphorylation
C)carbon fixation
D)photosystems I and II
E)noncyclic pathway of ATP formation

Question 28

The first event in photosynthesis is the ____.

A)movement of hydrogen ions through ATP synthase
B)absorption of a photon by a photosystem
C)fixation of carbon dioxide
D)breakdown of the thylakoid membrane
E)formation of phosphoglyceraldehyde

Question 29

The flow of hydrogen ions out of the thylakoid compartment ____.

A)provides energy to produce ATP molecules
B)recharges the photosystems
C)converts ATP into ADP
D)excites chlorophyll molecules
E)generates oxygen molecules

Question 30

Which plant(s) are adapted to hot, dry desert environments?

A)C3 plants only
B)C3 and C4 plants
C)plants that fix carbon only by the Calvin-Benson cycle
D)CAM plants
E)plants that are adapted to maximize photorespiration

Question 31

What is a key feature of autotrophs?

A)Autotrophs harvest energy directly from the environment.
B)Autotrophs do not require carbon.
C)Autotrophs obtain carbon from organic compounds.
D)Autotrophs harvest energy from decomposing organisms.
E)Autotrophs are consumers.

Question 32

Which subatomic particles of a pigment absorb light?

A)electrons only
B)protons only
C)neutrons only
D)electrons and protons
E)protons and neutrons

Question 33

The transport of ____ across the thylakoid membrane powers ATP production.

A)electrons
B)hydrogen ions
C)oxygen
D)carbon dioxide
E)phosphate ions

Question 34

-According to the accompanying diagram, which letter indicates the chloroplast membrane?

A)A
B)B
C)C
D)D
E)E

Question 35

​For each molecule of CO₂ that enters the Calvin-Benson cycle, ____ NADPH molecules are reduced and ____ molecules of ATP are split into ADP and P_i.

A)​two; two
B)​two; six
C)​six; two
D)​six; six
E)​five; one

Question 36

What role(s) do ATP and NADPH from the light-dependent reactions play in the conversion of PGA to PGAL in the Calvin-Benson cycle?

A)ATP donates a phosphate group and NADPH donates electrons and hydrogen.
B)ATP and NADPH both donate phosphate groups.
C)ATP provides electrons and NADPH provides a phosphate group.
D)ATP provides a carbon source and NADPH donates electrons and hydrogen.
E)ATP donates a phosphate group and NADPH provides a carbon source.

Question 37

Which type(s) of plants have adapted to hot, dry conditions by minimizing photorespiration?

A)C3 only
B)C4 only
C)CAM only
D)C3 and CAM
E)C4 and CAM

Question 38

How is the process of carbon fixation necessary for plant growth?

A)Carbon fixation extracts carbons from organic plant sugars to be used for energy.
B)Carbon fixation incorporates carbon from PGAL into sugar molecules.
C)Carbon fixation extracts carbon from an inorganic source (CO₂) and uses it to build sugars.
D)Carbon fixation extracts carbon from an inorganic source (CO₂) to produce O₂ needed for plant growth.
E)Carbon fixation regenerates carbon to be used in the light-dependent reactions for ATP production.

Question 39

What are the molecular reactants for photosynthesis in plants?

A)H₂O only
B)CO₂ only
C)O₂ only
D)both CO₂ and O₂
E)both CO₂ and H₂O

Question 40

Openings in leaves through which gases enter and exit are called ____.

A)mesophylls
B)stroma
C)rubiscos
D)stomata
E)photosystems

Question 41

ß-carotene ____.

A)absorbs yellow and orange light
B)is the major pigment found in plant cells
C)and chlorophyll a absorb light of the same wavelength
D)is an accessory pigment
E)reflects green light

Question 42

Match the description to the correct photosynthetic pathway.
a.light-dependent reactions in the noncyclic pathway
b.light-dependent reactions in the cyclic pathway
c.Calvin-Benson cycle
d.C4 pathway
e.photorespiration
This process involves a photolysis step, breaking water into hydrogen ions and oxygen.

Question 43

Match each process or structure with its correct location within the chloroplast. Some choices may be used more than once.
a.thylakoid membrane
b.stroma
c.thylakoid compartment
formation of ATP​

Question 44

Match each process or structure with its correct location within the chloroplast. Some choices may be used more than once.
a.thylakoid membrane
b.stroma
c.thylakoid compartment
Calvin-Benson cycle

Question 45

Match each process or structure with its correct location within the chloroplast. Some choices may be used more than once.
a.thylakoid membrane
b.stroma
c.thylakoid compartment
electron transport chain

Question 46

Which gas is released into the environment when organic material is burned?

A)O₂
B)CO₂
C)N₂
D)H₂
E)Cl₂

Question 47

Four of the five items listed below participate in photosynthesis. Select the exception.

A)photosystem
B)chlorophyll
C)mitochondrion
D)chloroplast
E)thylakoid membrane

Question 48

Match each process or structure with its correct location within the chloroplast. Some choices may be used more than once.
a.thylakoid membrane
b.stroma
c.thylakoid compartment
​photosystems I and II

Question 49

In the cyclic pathway of the light-dependent reactions, electrons ejected from photosystem I enter the electron transport system before returning to ____.

A)photosystem II
B)photosystem I
C)the stroma
D)the outer chloroplast membranes
E)ATP synthase

Question 50

Match the description to the correct photosynthetic pathway.
a.light-dependent reactions in the noncyclic pathway
b.light-dependent reactions in the cyclic pathway
c.Calvin-Benson cycle
d.C4 pathway
e.photorespiration
In this process, rubisco attaches oxygen (instead of carbon dioxide) to RuBP.

Question 51

The wavelength of visible light with the highest energy is ____.

A)violet
B)blue
C)yellow
D)orange
E)red

Question 52

Match the description to the correct photosynthetic pathway.
a.light-dependent reactions in the noncyclic pathway
b.light-dependent reactions in the cyclic pathway
c.Calvin-Benson cycle
d.C4 pathway
e.photorespiration
In this process, one six-carbon sugar is formed from two molecules of phosphoglyceraldehyde.

Question 53

-In the accompanying diagram, ATP synthase pumps hydrogen ions into which space?

A)A
B)B
C)C
D)D
E)E

Question 54

Electrons lost by chlorophyll are replaced by electrons donated from ____.

A)NADPH
B)sunlight
C)water
D)carbon dioxide
E)ATP

Question 55

Match each process or structure with its correct location within the chloroplast. Some choices may be used more than once.
a.thylakoid membrane
b.stroma
c.thylakoid compartment
accumulation of hydrogen ions

Question 56

Match each process or structure with its correct location within the chloroplast. Some choices may be used more than once.
a.thylakoid membrane
b.stroma
c.thylakoid compartment
​ATP synthase

Question 57

Match the description to the correct photosynthetic pathway.
a.light-dependent reactions in the noncyclic pathway
b.light-dependent reactions in the cyclic pathway
c.Calvin-Benson cycle
d.C4 pathway
e.photorespiration
This process yields ATP but not NADPH or oxygen.

Question 58

Match the description to the correct photosynthetic pathway.
a.light-dependent reactions in the noncyclic pathway
b.light-dependent reactions in the cyclic pathway
c.Calvin-Benson cycle
d.C4 pathway
e.photorespiration
In this process, carbon is fixed twice: once in mesophyll cells and again in bundle sheath cells.

Question 59

For each six atoms of carbon derived from CO₂ fixed in the light-independent reactions, how many molecules of PGAL (phosphoglyceraldehyde) are produced?

A)2
B)3
C)6
D)12
E)15

Question 60

The cyclic pathway of light-dependent reactions uses ____ to absorb light energy and emit electrons.​

A)​photosystems I and II
B)​photosystem II only
C)​photosystem I only
D)​ß-carotene
E)​ATP synthase

Question 61

Which energy sources drive the light-dependent and light-independent reactions of photosynthesis?

Question 62

-In the accompanying figure, what does letter E represent?

A)carbon dioxide
B)light energy
C)glucose
D)ATP
E)oxygen

Question 63

Match each process or structure with its correct location within the chloroplast. Some choices may be used more than once.
a.thylakoid membrane
b.stroma
c.thylakoid compartment
photolysis​

Question 64

-In the accompanying figure, letter D denotes which photosynthetic product?

Question 65

Match each term to its most suitable description.
a.absorbs light
b.converts light to chemical energy
c.organisms that make their own food
d.process that is minimized in C4 and CAM plants
e.​organisms that obtain energy from consuming other organisms
autotroph

Question 66

Match each term to its most suitable description.
a.absorbs light
b.converts light to chemical energy
c.organisms that make their own food
d.process that is minimized in C4 and CAM plants
e.​organisms that obtain energy from consuming other organisms
photorespiration

Question 67

Match each term to its most suitable description.
a.absorbs light
b.converts light to chemical energy
c.organisms that make their own food
d.process that is minimized in C4 and CAM plants
e.​organisms that obtain energy from consuming other organisms
heterotroph​

Question 68

How do C4 and CAM plants survive under dry conditions?

Question 69

Match the process to the correct description.

-formation of glucose

A)Rubisco attaches CO₂ to RuBP.
B)ATP and NADPH are required.
C)Two PGALs combine to form a six-carbon product.
D)O₂, ATP, and NADPH are produced.
E)An electron transport system produces ATP but not NADPH.

Question 70

Match the process to the correct description.
a.Rubisco attaches CO₂ to RuBP.b.ATP and NADPH are required.c.Two PGALs combine to form a six-carbon product.d.O₂, ATP, and NADPH are produced.e.An electron transport system produces ATP but not NADPH.
PGA to PGAL conversion

Question 71

Match each term to its most suitable description.
a.absorbs light
b.converts light to chemical energy
c.organisms that make their own food
d.process that is minimized in C4 and CAM plants
e.​organisms that obtain energy from consuming other organisms
photosynthesis

Question 72

Match each term to its most suitable description.
a.absorbs light
b.converts light to chemical energy
c.organisms that make their own food
d.process that is minimized in C4 and CAM plants
e.​organisms that obtain energy from consuming other organisms
pigment

Question 73

Match the process to the correct description.
a.Rubisco attaches CO₂ to RuBP.b.ATP and NADPH are required.c.Two PGALs combine to form a six-carbon product.d.O₂, ATP, and NADPH are produced.e.An electron transport system produces ATP but not NADPH.
carbon dioxide fixation

Question 74

-In the accompanying figure, the reactions at letter A ____.

A)are driven by ATP
B)generate water
C)require NADPH
D)are dependent on light
E)comprise the Calvin-Benson cycle

Question 75

What is the chemical relationship between the light-dependent and light-independent reactions of photosynthesis?

Question 76

Match the process to the correct description.
a.Rubisco attaches CO₂ to RuBP.b.ATP and NADPH are required.c.Two PGALs combine to form a six-carbon product.d.O₂, ATP, and NADPH are produced.e.An electron transport system produces ATP but not NADPH.
cyclic pathway

Question 77

A cat eats a bird, which ate a caterpillar, which chewed on a weed. Which organisms are autotrophs? Which ones are heterotrophs?

Question 78

Match the process to the correct description.
a.Rubisco attaches CO₂ to RuBP.b.ATP and NADPH are required.c.Two PGALs combine to form a six-carbon product.d.O₂, ATP, and NADPH are produced.e.An electron transport system produces ATP but not NADPH.
noncyclic pathway

Question 79

How did Theodor Engelmann determine which colors of light were optimal for driving photosynthesis?

Question 80

What do photosynthetic autotrophs use as a carbon source? What do they use as an energy source?